Method for reducing uncomfortable and peculiar smell components in coffee baked beans

Abstract

Provided is a technique whereby the formation of indole and skatole, which are known as unpleasant odor components, in roasted coffee beans can be suppressed without heating green coffee beans at a high temperature of 100 DEG C or higher. More specifically, in the present invention, green coffee beans are moistened with water, heat-treated at atmospheric pressure and a temperature of less than 100 DEG C, the heat-treated green coffee beans are allowed to absorb organic acids and / or saccharides, and then baked.

Description

Technical Field

[0001] The present invention relates to a method for reducing unpleasant odor components in roasted coffee beans. More specifically, the present invention provides a method for reducing unpleasant odor components generated in a subsequent roasting step by adding water, heating, and adding an organic acid and / or sugar to green coffee beans. Background Art

[0002] Coffee is a favorite beverage consumed around the world, and coffee with a balanced aroma, sweetness, bitterness, and sourness is highly sought after. The subtle differences in the conditions during the selection, roasting, and extraction of raw coffee beans will lead to significant differences in the hundreds of ingredients that determine the taste, aroma, and richness. Coffee is a delicate and elegant drink.

[0003] There are three native species of coffee: Arabica, Robusta, and Liberica. Arabica is produced in Ethiopia, Brazil, Colombia, and other Central and South America, Hawaii, India, etc., which are the countries of origin. It accounts for more than 70% of the world's coffee production. It has excellent aroma and acidity and is known as high-quality coffee. Robusta is produced in Congo and other African places, Indonesia, Trinidad and Tobago, etc., which account for about 30% of the world's coffee production. It has very high yield and is used for instant coffee, canned coffee, etc. Robusta coffee beans have an earthy and musty smell, so it is considered to be inferior to Arabica in quality. Liberica is produced in the Republic of Liberia, Ivory Coast, Angola, Indonesia, Liberia, etc. on the west coast of Africa, which is the place of origin. It only accounts for about a few percent of the world's coffee production and is basically consumed only in the cultivation area.

[0004] As a method for removing the earthy and musty smell of Robusta coffee beans and effectively improving their quality, the following method is known: moist Robusta green coffee beans are steamed at 260 to 300°F (about 126 to 149°C) under a pressure exceeding atmospheric pressure, and the treated beans are roasted to improve the quality of roasted Robusta coffee beans (Patent Document 1). In this document, the cause of the earthy and musty smell is considered to be 2-methylisoborneol. As another method for improving the quality of coffee beans, the following technology is disclosed: after adding sugars and amino acids to green coffee beans, heat treatment is performed under a pressure above atmospheric pressure (for example, Patent Documents 2 and 3).

[0005] Patent Document 4 discloses a method for increasing the β-damascenone content in green coffee beans by subjecting green coffee beans to an acid-treated high-temperature and high-pressure treatment step in which green coffee beans are treated with a gas containing water vapor at a temperature of 100 to 200° C. and a pressure (gauge pressure) exceeding 0 MPa. This method enables the production of green coffee beans and roasted coffee beans with enhanced sweetness and flavor.

[0006] These methods are processing methods that require equipment capable of high-temperature heating under pressure.

[0007] Subsequently, regardless of the variety of coffee beans, green coffee beans obtained from unripe berries contain a large amount of tryptophan, and as the berries gradually mature, the content decreases, and it has been confirmed that indole and skatole produced in the thermal decomposition products of tryptophan during roasting are the unpleasant odor components of coffee (Patent Document 5). Patent Document 5 provides a method for obtaining roasted coffee beans with low indole and skatole contents by selecting green coffee beans with low tryptophan content as raw materials using a near infrared method.

[0008] On the other hand, Patent Document 6 discloses a method for reducing aroma components such as indole and skatole, which are considered to be the cause of unpleasant odors, in roasted coffee beans by soaking green coffee beans in sake lees and then roasting them.

[0009] In this method, in order to suppress the modification of sake lees containing various components, the contact between the green coffee beans and sake lees is preferably carried out in a temperature environment of 0 to 30°C, and the alcohol content in the immersion liquid for immersing the green coffee beans is preferably 0.5 to 4% by mass. It was also shown that the longer the immersion time in sake lees, the greater the effect of reducing the unpleasant taste, and the immersion time is particularly preferably 16 hours or more.

[0010] Prior art literature

[0011] Patent Literature

[0012] Patent Document 1: Japanese Patent Application Laid-Open No. 6-303905

[0013] Patent Document 2: Japanese Patent Application Publication No. 2000-342182

[0014] Patent Document 3: Japanese Patent Application Publication No. 2010-166868

[0015] Patent Document 4: Japanese Patent Application Publication No. 2018-057369

[0016] Patent Document 5: Japanese Patent Application Publication No. 2016-167993

[0017] Patent Document 6: Japanese Patent Application Publication No. 2022-015956

[0018] Non-patent literature

[0019] Non-patent document 1: Toshiki Minetoki, Brewing Association, Vol. 109, No. 1, pp. 11-20 (2014)

[0020] Non-patent document 2: Nagata Hiromitsu et al., Toyo Food Industry Junior University / Toyo Food Research Institute Research Report, 20, 27-34 (1994)

[0021] Non-patent document 3: Takaya Mutsuko et al., Shokuei Gakuin University Bulletin No. 60, pp. 19-29, received on September 15, 2010 Summary of the invention

[0022] Problem that the invention aims to solve

[0023] The present invention provides a technology for suppressing the formation of indole and skatole, which are known as unpleasant odor components, in roasted coffee beans without heating green coffee beans at a high temperature of 100° C. or higher.

[0024] Solutions for solving problems

[0025] The present invention generally involves adding water to green coffee beans, and then performing a heating treatment at a temperature lower than 100° C. under atmospheric pressure to allow the water to penetrate into the green coffee beans, causing the green coffee beans impregnated with water to absorb organic acids and sugars, and then roasting the beans, thereby suppressing the formation of indole and skatole in the roasted coffee beans. As a result, the content of indole and skatole in the roasted coffee beans is reduced compared to the content of indole and skatole in the roasted coffee beans obtained by roasting the green coffee beans before processing.

[0026] More specifically, the present invention provides the following techniques.

[0027] [1] A method for producing roasted coffee beans, comprising the following steps:

[0028] (1) A step of adding 10% by mass or more of water to green coffee beans;

[0029] (2) After the aforementioned step of adding water, the step of heating the green coffee beans and the water to a temperature lower than 100° C. under atmospheric pressure to allow the water to penetrate into the green coffee beans;

[0030] (3) after the aforementioned impregnation step, a step of allowing the green coffee beans impregnated with water to absorb organic acids and / or sugars; and

[0031] (4) After the step of absorbing the organic acid and / or sugar, the step of roasting the green coffee beans that have absorbed the organic acid and / or sugar.

[0032] [2] The production method according to item 1, wherein in the step of absorbing the organic acid and / or sugar, the aqueous solution containing the organic acid and / or sugar is impregnated into the green coffee beans impregnated with water.

[0033] [3] The production method according to item 1 or 2, wherein the organic acid is at least one selected from the group consisting of lactic acid, citric acid and acetic acid, and the sugar is at least one selected from the group consisting of glucose, fructose and maltose.

[0034] [4] The production method according to any one of items 1 to 3, wherein 0.5% by mass or more of the organic acid or sugar is absorbed based on the green coffee beans.

[0035] [5] The production method according to any one of items 1 to 4, wherein the green coffee beans are Robusta beans.

[0036] [6] Roasted coffee beans produced by the production method according to any one of items 1 to 5.

[0037] [7] A food or beverage comprising the roasted coffee beans or an extract thereof according to item 6.

[0038] [8] A method for reducing indole and skatole in roasted coffee beans, comprising the following steps:

[0039] (1) A step of adding 10% by mass or more of water to green coffee beans;

[0040] (2) After the aforementioned step of adding water, the step of heating the green coffee beans and the water to a temperature lower than 100° C. under atmospheric pressure to allow the water to penetrate into the green coffee beans;

[0041] (3) after the aforementioned impregnation step, a step of allowing the green coffee beans impregnated with water to absorb organic acids and / or sugars; and

[0042] (4) After the step of absorbing the organic acid and / or sugar, the step of roasting the green coffee beans that have absorbed the organic acid and / or sugar.

[0043] The roasted coffee beans produced by the production method of the present invention can be extracted under normal conditions. The roasting conditions are not particularly limited as long as they are normal conditions, and for example, the roasting conditions described in Non-Patent Document 3 can be referred to.

[0044] The roasted coffee beans or their extracts obtained in this way can be added to various beverages and foods such as coffee, coffee drinks, coffee-containing soft drinks, coffee-containing carbonated drinks, instant coffee, coffee concentrate, milk drinks, dairy products, cream, desserts, and stuffed Japanese desserts.

[0045] Effects of the Invention

[0046] In the prior art, it is necessary to heat the green coffee beans at a high temperature of 100°C or higher, but according to the present invention, the formation of specific unpleasant odor components (indole and skatole) generated in the roasted coffee beans can be suppressed in a short time under heating conditions below 100°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a graph comparing the effect of adding organic acids to Robusta green coffee beans (from Vietnam) relative to the indole (upper panel) and skatole (lower panel) contents of each sample.

[0048] Figure 2 This is a graph comparing the effect of the amount of water added to Robusta green coffee beans (from Vietnam) on the indole (upper panel) and skatole (lower panel) contents of each sample.

[0049] Figure 3 This is a graph comparing the effect of the amount of organic acid added to Robusta green coffee beans (produced in Vietnam) on the indole (upper panel) and skatole (lower panel) contents of each sample.

[0050] Figure 4 This is a graph comparing the effect of adding sugars to Robusta green coffee beans (from Vietnam) relative to the indole (upper panel) and skatole (lower panel) content of each sample.

[0051] Figure 5 This is a graph comparing the effect of the amount of water added to Robusta green coffee beans (from Vietnam) on the indole (upper panel) and skatole (lower panel) contents of each sample.

[0052] Figure 6 This is a graph comparing the effect of the amount of sugar added to Robusta green coffee beans (produced in Vietnam) on the indole (upper panel) and skatole (lower panel) contents of each sample.

[0053] Figure 7 This is a graph comparing the effects of adding organic acids and sugars to Robusta green coffee beans (from Vietnam) relative to the indole (upper panel) and skatole (lower panel) contents of each sample.

[0054] Figure 8 This is a graph comparing the effect of the amount of water added to Robusta green coffee beans (from Vietnam) on the indole (upper panel) and skatole (lower panel) contents of each sample.

[0055] Fig. 9A graph comparing the effects of adding organic acids and sugars to Robusta green coffee beans (from Uganda) and Robusta green coffee beans (from Indonesia) relative to the indole (upper panel) and skatole (lower panel) contents of each sample.

[0056] Fig.10 This is a graph comparing the effects of adding organic acids and sugars to Arabica green coffee beans (from Brazil) relative to the indole (upper panel) and skatole (lower panel) contents of each sample.

[0057] Fig.11 This is a graph comparing the effects of allowing Robusta green coffee beans (produced in Vietnam) to absorb organic acids and sugars with or without drying, relative to the indole (upper panel) and skatole (lower panel) contents of each sample. DETAILED DESCRIPTION

[0058] 1. Green coffee beans used in the present invention

[0059] The type of green coffee beans used as the subject of the present invention is not limited, and may be Arabica, Robusta, or Liberica, and the origin is not particularly limited. Examples of green coffee beans include Arabica produced in Central and South America, such as Ethiopia, Brazil, and Colombia, Hawaii, and India; Robusta produced in various parts of Africa, such as Congo, Indonesia, and Trinidad and Tobago; and Liberica produced in the Republic of Liberia, Ivory Coast, Angola, Indonesia, and Liberia on the west coast of Africa. Examples of green coffee bean brands include Kilimanjaro, Blue Mountain, Emerald Hill, Mocha, Brazil, Guatemala, Colombia, Hawaii Kona, Mandheling, and Costa Rica. The moisture content of green coffee beans is not particularly limited, and is, for example, 9 to 13% by mass, and is usually 10 to 12% by mass.

[0060] The present invention aims to reduce indole and skatole that deteriorate the quality of roasted coffee beans. Therefore, the present invention is useful when applied to Robusta coffee, which has a high content of tryptophan, a precursor of these components, and is classified as low-grade coffee, because the effect of the present invention is well exerted. However, it can also be applied to green coffee beans classified as commercial coffee or higher grades.

[0061] In addition, the green coffee beans to which the present invention is applied may be in the form of beans or in the form of ground coffee.

[0062] 2. The method for producing roasted coffee beans of the present invention

[0063] The method for producing roasted coffee beans according to the present invention is characterized in that it comprises the following steps:

[0064] (1) A step of adding 10% by mass or more of water to green coffee beans;

[0065] (2) after the step of adding the water, heating the green coffee beans and the water to a temperature lower than 100° C. under atmospheric pressure to allow the water to penetrate into the green coffee beans;

[0066] (3) after the step of impregnating the green coffee beans with water, allowing the green coffee beans impregnated with water to absorb organic acids and / or sugars; and

[0067] (4) After the step of absorbing the organic acid and / or sugar, the step of roasting the green coffee beans that have absorbed the organic acid and / or sugar.

[0068] By undergoing the above steps, the content of indole and skatole in the roasted coffee beans is reduced compared to the content of indole and skatole in the roasted coffee beans obtained by roasting the unprocessed green coffee beans. In the present specification, "unprocessed green coffee beans" refer to the coffee beans before undergoing the above step (1). In the present specification, "processed green coffee beans" refer to the coffee beans after undergoing the above steps (1) to (3).

[0069] Indole and skatole are said to be generated by thermal decomposition of tryptophan contained in green coffee beans. Therefore, it is speculated that in the present invention, the thermal decomposition of tryptophan itself is suppressed by allowing the green coffee beans before roasting to absorb organic acids and sugars, or the reaction of tryptophan with other components contained in the green coffee beans is promoted, thereby suppressing the formation of indole and skatole. It is also speculated that in the present invention, the green coffee beans are in a state of being impregnated with water by undergoing the above steps (1) and (2), and then the step (3) of allowing the green coffee beans to absorb organic acids and sugars is performed. Therefore, the organic acids and sugars are easily impregnated into the green coffee beans, and the formation of the above indole and skatole is suppressed in the green coffee beans. Therefore, compared with the case where the green coffee beans are allowed to absorb organic acids and sugars without undergoing both or one of the above steps (1) and (2), the present invention is superior in suppressing the formation of indole and skatole.

[0070] (1) Process of adding water to green coffee beans

[0071] In the present invention, “adding 10% by mass or more of moisture to green coffee beans” means that green coffee beans and a predetermined amount of moisture coexist in a container.

[0072] More specifically, green coffee beans as the object and a predetermined amount of water are put into a container. As a container, any form of intermittent or continuous type can be used as long as it can heat and mix the green coffee beans with water. For example, a pot, a kettle or a large kettle, a cooking device with heating means and / or stirring means in the pot or kettle, a wet mixing device with stirring blades, a mixer for food cooking or medicine manufacturing with a mixing plate inside the container and the container itself being able to rotate, a cylindrical stirrer designed in a way that the materials flow and mix along the blades in the mixing tank and mix the materials gently without destroying them, a solid culture device containing a ventilated culture bed, etc. These devices may further have a pressurizing means and a spraying means. In addition, in order to prevent the water from escaping, the container may be covered. In the present invention, the cover may be a gate cover such as a heat-resistant film such as aluminum foil, or an embedded cover that closes the opening of the container. In addition, the large device described above may be made into an airtight structure. In the present invention, heating to 100° C. or higher under pressure is not intended. However, in this case, a heat-resistant container is preferably used as the container, and an autoclave may be used as the heat-resistant container.

[0073] In the present invention, regardless of the type of green coffee beans or the amount of moisture in the green coffee beans when adding water, 10% by mass or more, preferably 20% by mass or more, and more preferably 30% by mass or more of water is added relative to the mass of the green coffee beans as the object. The upper limit of the amount of water added relative to the unit mass of the green coffee beans as the object is not limited, but is 100% by mass or less, preferably 75% by mass or less, and more preferably 60% by mass or less. If 10% by mass or more of water is added and the roasted coffee beans are treated under the conditions specified in the present invention, the content of indole and skatole in the roasted coffee beans is significantly reduced compared to roasted coffee beans produced without performing all the treatments under the conditions specified in the present invention. If 75% by mass or less of water is added, substantially all of the water is absorbed by the green coffee beans. In the present invention, the amount of water added relative to the mass of the green coffee beans as the object is, for example, 10% by mass or more, 10 to 100% by mass, 10 to 75% by mass, 20 to 65% by mass, 20 to 60% by mass, or 30 to 60% by mass.

[0074] As the water to be added, water such as pure water, ultrapure water, ion exchange water, filtered water, well water, natural water, mineral water, tap water or mixed water thereof can be used. Regarding the temperature of the water to be added, under atmospheric pressure, the lower limit is higher than the freezing point of water, and the upper limit is lower than the boiling point of water 100°C. Other than that, there is no particular limitation. It can be cold water lower than room temperature, water around room temperature, warm water higher than room temperature, or high-temperature water. In the present invention, the temperature of the water to be added is, for example, above 0°C and lower than 100°C, 0 to 99°C, 5 to 99°C or 5 to 95°C. Among them, if it is in the temperature range of 1 to 35°C, 1 to 30°C, 1 to 15°C, 5 to 35°C, 5 to 30°C, 15 to 35°C, 15 to 30°C or 15 to 25°C, it is possible to work at room temperature or normal temperature in the working environment or in a cold place.

[0075] In the present invention, "room temperature" means 1 to 35°C, "normal temperature" means 15 to 35°C, and "cold place" means "1 to 15°C".

[0076] In addition, in this specification, the symbol "-" which connects an upper limit value and a lower limit value includes both the upper limit value and the lower limit value. For example, "A-B" means A or more and B or less.

[0077] The water to be added may be a prepared solution obtained by mixing the above-mentioned water with spices (e.g., cocoa, cinnamon, vanilla, coriander, cardamom, cloves, ginger, nutmeg, allspice, garlic, camphor), herbs (e.g., rosemary, mint, basil, lemongrass, hops, jasmine, lavender, bergamot, lilac, orange peel), tea (e.g., green tea, oolong tea, Pu'er tea, black tea), cereals (e.g., rice, barley, malt, coix), vegetables (e.g., tomatoes, eggplants, green peppers, red peppers, carrots, pumpkins, cucumbers, burdocks, kidney beans, peas, soybeans, sweet potatoes), fruits (e.g., pineapples, apples, strawberries, bananas, grapes, peaches, raspberries, cherries, blueberries, mangoes, oranges, lemons, grapefruits, apricots), or peels, seeds, and the like of vegetables or fruits. The amount of water added when added in the form of a prepared solution refers to the amount of water contained in the added prepared solution. The amount of the above-mentioned materials mixed in the preparation liquid is not particularly limited and can be appropriately adjusted according to the shape of the materials, etc. By using such a preparation liquid, the characteristic aroma of the above-mentioned materials can be effectively imparted to the green coffee beans. As spices, herbs, tea, cereals, vegetables, fruits, peels or seeds of vegetables or fruits, etc. that can be used as the above-mentioned materials, they can be appropriately selected according to the target aroma imparted to the green coffee beans, and materials that can be generally obtained can be used. The above-mentioned materials can be used in their original shape or size, or they can be processed into a specific shape or size for use. From the aspect of easy mixing with water, it is preferably made into any powder shape for use. As the above-mentioned materials, spices or herbs are preferably used from the aspect of rich aroma components and excellent improvement or enhancement of coffee aroma.

[0078] (2) Step of impregnating green coffee beans with water

[0079] In the present invention, “heating the green coffee beans and water to a temperature lower than 100° C. under atmospheric pressure to allow the water to penetrate into the green coffee beans” means that the green coffee beans and the added water are heated from room temperature to a set temperature lower than 100° C. without applying pressure, and as a result, the added water is penetrated into the inside of the green coffee beans. At this time, the water may adhere to the outer surface of the green coffee beans, and then, excess water may exist outside the green coffee beans. In this specification, allowing the added water to penetrate into the inside of the green coffee beans is sometimes simply referred to as “adding water”.

[0080] More specifically, the green coffee beans and a predetermined amount of added water put into a container (preferably a heat-resistant container) are heated from the temperature of the added water, for example, room temperature (1 to 35°C) to a set temperature lower than 100°C under atmospheric pressure without applying pressure, so that the water is impregnated into the green coffee beans. The upper limit of the set temperature is lower than 100°C, preferably 99°C or lower, and more preferably 95°C or lower. The lower limit of the set temperature is not particularly limited as long as it is a temperature higher than room temperature, and is, for example, 35°C or higher, preferably 50°C or higher, and more preferably 60°C or higher from the perspective of promoting the penetration of water into the green coffee beans. In the present invention, the range of the set temperature is, for example, 35°C or higher and lower than 100°C, 35°C to 99°C, 40°C to 99°C, 50°C to 95°C, and 60°C to 95°C.

[0081] Regarding the heating time and temperature raising process of the green coffee beans and water, there are no particular limitations as long as the water penetrates into the green coffee beans. Depending on the weight of the green coffee beans to be treated, the lower limit is 5 minutes or more, preferably 10 minutes or more, and more preferably 15 minutes or more (for example, 30 minutes or more). The upper limit is less than 16 hours, preferably 15 hours or less, more preferably 6 hours or less, and even more preferably 3 hours or less. If the heating time is 5 minutes or more, a sufficient amount of water is absorbed by the green coffee beans. In the present invention, the time for water to penetrate into the green coffee beans is, for example, 5 minutes or more and less than 16 hours, 5 minutes to 15 hours, 5 minutes to 6 hours, 10 minutes to 3 hours, or 10 minutes to 2 hours, or 30 minutes or more and less than 16 hours.

[0082] Heating can be done by applying thermal energy to the green coffee beans and the coexisting water to increase the temperature of the inside of the green coffee beans and the water. Examples of the application of thermal energy include a steaming method in which steam is directly brought into contact with the green coffee beans, and a method in which the temperature of the green coffee beans and the water is increased by heating the entire container.

[0083] (3) Step of absorbing organic acids and / or sugars

[0084] In the present invention, “allowing green coffee beans to absorb organic acids and / or sugars” includes not only adding organic acids and / or sugars to green coffee beans and then allowing the inside of the green coffee beans to absorb the organic acids and / or sugars, but also allowing the organic acids and / or sugars to adhere to the outer surface of the green coffee beans, and means that the organic acids and / or sugars are in a state where they can act on the components of the green coffee beans.

[0085] As the organic acid that can be used in the present invention, there is no particular limitation as long as it is edible. Examples of the organic acid include lactic acid, citric acid, acetic acid, propionic acid, butyric acid, oxalic acid, malonic acid, gluconic acid, malic acid, tartaric acid, fumaric acid, succinic acid, adipic acid, etc. From the aspect of excellent effect of inhibiting the formation of indole and skatole, lactic acid, citric acid and acetic acid are preferred, and lactic acid is more preferred.

[0086] Sugars that can be used in the present invention are monosaccharides and disaccharides, preferably monosaccharides. As monosaccharides, for example, glucose (dextrose), fructose (levulose), galactose, xylose, arabinose, tagatose, etc. can be listed, and as disaccharides, for example, sucrose, lactose, maltose (maltose), isomaltose, trehalose, cellobiose, etc. can be listed. From the aspect of excellent effect of inhibiting the formation of indole and skatole, glucose, fructose and maltose are preferred, and fructose and glucose are more preferred.

[0087] The organic acid may be used alone or in combination of multiple organic acids. When multiple organic acids are used in combination, the type and ratio of the organic acids combined are not particularly limited. From the perspective of excellent effects of inhibiting the formation of indole and skatole, the organic acid preferably contains at least one of lactic acid, citric acid and acetic acid, more preferably contains at least lactic acid, further preferably contains 30% by mass or more of lactic acid, and further preferably contains 50% by mass or more of lactic acid.

[0088] The sugar may be used alone or in combination of multiple sugars. When multiple sugars are used in combination, the types and ratios of the combined sugars are not particularly limited. From the perspective of excellent effects of inhibiting the formation of indole and skatole, the sugar preferably contains at least one of glucose, fructose, and maltose, more preferably contains glucose or fructose, further preferably contains at least glucose, further preferably contains 30% by mass or more of glucose, and particularly preferably contains 50% by mass or more of glucose.

[0089] In Patent Document 6, green coffee beans are immersed in sake lees to reduce aroma components such as indole and skatole in roasted coffee beans that are considered to be the cause of unpleasant odors. It is known that sake lees contain various organic acids and other components such as sugars and amino acids (for example, non-patent documents 1 and 2). However, the organic acids and sugars contained in sake lees are extremely trace, for example, lactic acid is 74 mg / 100g, acetic acid is about 30 mg / 100g, and the total organic acid content is 189-418 mg / 100g. In addition, glucose is about 15%. In addition, the type and composition of the components contained in sake lees affect various manufacturing conditions such as the type and composition of fermentation raw materials, the type of koji used in koji, and fermentation conditions. sake lees usually contain water, carbohydrates, proteins, lipids, ash, and various vitamins, but it is not clear which component helps to reduce unpleasant odors.

[0090] Organic acids and / or sugars are added to the green coffee beans impregnated with water as described above, and then the organic acids and / or sugars are impregnated into the interior of the green coffee beans and adhered to the outer surfaces of the green coffee beans. In this way, the organic acids and / or sugars adhered to the interior and outer surfaces of the green coffee beans can act on the components of the green coffee beans. In the present invention, the total amount of the organic acids and / or sugars impregnated into the interior of the green coffee beans and the amount of the organic acids and / or sugars adhered to the outer surfaces of the green coffee beans is defined as the amount of organic acids and / or sugars absorbed by the green coffee beans.

[0091] The organic acid or sugar (total amount of organic acid or sugar) is absorbed by 0.5% or more, preferably 0.7% or more, and more preferably 1.0% or more, based on the following limit, relative to the mass of the green coffee beans before processing. The upper limit of the amount of organic acid or sugar absorbed relative to the mass of the green coffee beans before processing is not limited, but is 10% or less, 5% or less. If 10% or less of organic acid or sugar is added, substantially all of the organic acid or sugar is absorbed by the green coffee beans. If the roasted coffee beans are processed under the conditions specified in the present invention except that 0.5% or more of organic acid or sugar is absorbed in total, the content of indole and skatole in the roasted coffee beans is significantly reduced compared to roasted coffee beans produced without being processed under all the conditions specified in the present invention. In the present invention, the amount of organic acid or sugar added relative to the mass of green coffee beans before processing is, for example, 0.5% by mass or more, 0.7% by mass or more, 1.0% by mass or more, 0.5 to 10% by mass, 0.7 to 10% by mass, 0.7 to 5% by mass, or 1.0 to 5% by mass.

[0092] The organic acid and the sugar can be used in combination. When used in combination, the above amounts can be absorbed by the green coffee beans. The ratio (mass ratio) of the organic acid and the sugar when used in combination is not particularly limited, and for example, the organic acid:sugar ratio is in the range of 99:1 to 1:99, preferably in the range of 90:10 to 10:90, and more preferably in the range of 80:20 to 20:80.

[0093] In the step of adding the organic acid and / or sugar, the organic acid and / or sugar may be directly added to the coffee beans and absorbed. If an aqueous solution containing the organic acid and / or sugar is added to the green coffee beans, the beans can be uniformly absorbed. The concentration of the organic acid or sugar in the aqueous solution is not particularly limited as long as a predetermined amount of the organic acid and / or sugar is absorbed into the green coffee beans and adheres to the outer surface thereof. For example, the lower limit of the concentration of the organic acid or sugar in the aqueous solution is 10% by mass or more, preferably 20% by mass or more, and more preferably 50% by mass or more. It depends on the amount of water absorbed by the green coffee beans, but as long as the concentration of the organic acid or sugar in the aqueous solution is 10% by mass or more, the predetermined amount of the organic acid and / or sugar will be absorbed by the green coffee beans and can adhere to the outer surface thereof.

[0094] The conditions such as temperature and time in the step of adding the organic acid and / or sugar are not particularly limited as long as the organic acid and / or sugar is absorbed by the green coffee beans, and the step can be carried out under any conditions. For example, the temperature is room temperature (1 to 35° C.) to 90° C., preferably 15 to 85° C., and the time is 30 minutes or more and less than 16 hours, preferably 30 minutes to 12 hours, and more preferably 1 to 6 hours.

[0095] (4) A step of roasting the green coffee beans that have absorbed organic acids and / or sugars

[0096] In the present invention, “roasting the green coffee beans that have absorbed the organic acid and / or sugar” means: putting the green coffee beans into a roaster, adjusting the heat in the roaster, and applying thermal energy to the green coffee beans.

[0097] In the present invention, the roasting conditions such as roasting temperature and roasting environment are not particularly limited as long as they are common conditions, and the roasting conditions described in non-patent document 3 can be referred to. By setting the roasting temperature to 190-240°C and controlling the temperature curve before and after roasting, it is possible to adjust the flavors such as sourness, bitterness, and richness. In the present invention, the roasting degree of roasted coffee beans is not particularly limited, and is specified by the L value measured under the following conditions. The L value refers to the value of "L" representing brightness in the Lab standard specified by the International Commission on Illumination. Regarding the reference L value relative to the roasting degree, for example, it is 27.0 or more in light roasting (light roast), 18.5 or more and less than 20.5 in medium roasting (city roast), and 15.0 or more and less than 16.5 in deep roasting (French roast). In the present invention, the roasting device and the heating method are not particularly limited, and known roasting devices and heating methods such as direct fire, semi-hot air, and hot air can be used.

[0098] (5) Step of drying the green coffee beans that have absorbed organic acids and / or sugars

[0099] After the step of allowing the wet green coffee beans that have absorbed moisture through the above-mentioned step to absorb the aforementioned organic acid and / or sugar, during the period until roasting, the green coffee beans may be dried before roasting, or may be roasted without drying the green coffee beans. There is no particular limitation on the drying method when drying the green coffee beans, and those skilled in the art may set it appropriately. For example, the green coffee beans may be dried by hot air using a food dryer or by methods such as fluidized bed drying or natural drying. The drying conditions may be appropriately set by those skilled in the art, for example, they may be dried at 60°C to 80°C for 1 to 4 hours. The degree of drying may be the same as the moisture content of the green coffee beans before processing (e.g., 9 to 13% by mass), or it may be balanced with the roasting process and increased or decreased in a manner that the moisture content is different from the moisture content of the green beans before processing.

[0100] In the present invention, the green coffee beans in a wet state can be directly applied to the roasting process without the need for a drying process. By appropriately setting the roasting conditions according to the wetness and dryness of the green coffee beans, roasted coffee beans of a desired roasting degree can be obtained.

[0101] It was confirmed that the roasted coffee beans obtained in this manner had significantly lower contents of indole and skatole, which are unpleasant odor components, and had an improved grade in the flavor evaluation, compared to roasted coffee beans produced by a conventional production method.

[0102] Hereinafter, the present invention will be described using control examples, embodiments and comparative examples, but the present invention is not limited thereto, and it should be understood that any modifications and additions may be made as long as the purpose of the present invention is not hindered, and the present invention may be used in combination with other techniques.

[0103] Example

[0104] Experiment 1 Effect of adding organic acids to green coffee beans

[0105] (1) Roasted coffee beans

[0106] [Comparison A]

[0107] 100 g of Robusta green coffee beans (produced in Vietnam) were roasted at 235° C. using Gene Cafe (manufactured by JENESIS) until the L value reached 20, thereby obtaining roasted coffee beans (Vietnam Robusta control A).

[0108] [Comparison B]

[0109] 100 g of green coffee beans of the Robusta species (produced in Vietnam) and 40 g of water at room temperature were placed in a heat-resistant container, which was covered with aluminum foil to prevent the water from escaping. The heat-resistant container was placed in an autoclave (LSX500, TOMY SEIKO Co., Ltd.), the temperature was raised from room temperature to 90° C., and the temperature was maintained for 30 minutes to perform a heat treatment.

[0110] Thereafter, the coffee beans were dried to a moisture content of about the amount before processing, and the obtained dried green coffee beans were roasted at 235° C. using Gene Cafe (manufactured by JENESIS) until the L value reached 20, thereby obtaining roasted coffee beans (Vietnamese Robusta control B).

[0111] It should be noted that in the experimental items, the roasting conditions were unified into a medium roasting condition with an L value of 20 in order to easily identify the changes in the indole and skatole contents in the roasted coffee beans. In the present invention, the degree of roasting is not limited.

[0112] [Samples 1-1 to 1-3]

[0113] 100 g of green coffee beans of the Robusta species (produced in Vietnam) and 40 g of water at room temperature were placed in a heat-resistant container, which was covered with aluminum foil to prevent the water from escaping. The heat-resistant container was placed in an autoclave (LSX500, TOMY SEIKO Co., Ltd.), the temperature was raised from room temperature to 90° C., and the temperature was maintained for 30 minutes to perform a heat treatment.

[0114] 3 g of an organic acid (lactic acid, citric acid, or acetic acid) was added to the heat-treated green coffee beans based on 100 g of the green coffee beans before processing, and the mixture was left to be absorbed at room temperature for 3 hours.

[0115] Thereafter, the coffee beans were dried to a moisture content of about the amount before processing, and the dried processed green coffee beans obtained were roasted at 235° C. using Gene Cafe (manufactured by JENESIS) until the L value reached 20, thereby obtaining roasted coffee beans (Vietnamese Robusta samples 1-1 to 1-3).

[0116] (2) Coffee extract

[0117] For controls A and B and samples 1-1 to 1-3, each roasted coffee bean was crushed to the minimum particle size of a cone mill (DeLonghi SpA) to obtain a roasted bean powder. After 180 mL of hot water was poured into 10 g of the roasted bean powder and kept for 4 minutes, the whole was stirred and mixed to remove the bubbles remaining on the surface. Thereafter, the mixture was kept for 12 minutes from the time of the hot water injection (ie, the extraction time was set to 12 minutes), and the supernatant after the roasted bean powder was naturally precipitated was recovered as a coffee extract.

[0118] (3) Determination of indole and skatole content in coffee extract

[0119] 3-methyl-1H-indole-d8 (obtained from Toronto Research Chemicals Inc.) was dissolved in 50% methanol aqueous solution by volume at a concentration of 100 ng / mL as an internal standard solution. After mixing 25 μL of the internal standard solution, 400 μL of 50% methanol aqueous solution by volume and 100 μL of each coffee extract, the mixture was filtered using a PTFE filter with a pore size of 0.2 μm, and the filtrate was used as an analytical sample. For the analytical sample, the content of indole and skatole was determined according to the following LC-MS / MS conditions. The number of data for each condition was set to 3, and the average value was calculated and used as the quantitative value.

[0120] (4) Measurement results

[0121] The quantitative values ​​and standard deviations of indole and skatole for each sample are summarized in Table 1. Figure 1 A comparison chart of the quantitative values ​​of indole (upper panel) and skatole (lower panel) of each sample is shown in FIG.

[0122] [Table 1]

[0123]

[0124] (5) Investigation

[0125] It was confirmed that the content of indole or skatole in the extract obtained from the green coffee beans of the examples processed by adding water, heating and adding an organic acid was significantly lower than that of the extract obtained from any of the control examples. It was confirmed that the content of indole or skatole was significantly lowered when lactic acid was used as the organic acid.

[0126] Experiment 2 Effect of the amount of water added to green coffee beans

[0127] (1) Roasted coffee beans

[0128] [Sample 2-1]

[0129] 100 g of Robusta green coffee beans (produced in Vietnam) were placed in a heat-resistant container and covered with aluminum foil to prevent moisture from escaping. The heat-resistant container was placed in an autoclave (LSX500, TOMY SEIKO Co., Ltd.), and the temperature was raised from room temperature to 90° C. and maintained at this temperature for 30 minutes to perform a heat treatment.

[0130] 3 g of lactic acid was added to the heat-treated green coffee beans based on 100 g of the green coffee beans before processing, and the mixture was left to be absorbed at room temperature for 3 hours.

[0131] Thereafter, the coffee beans were dried to a moisture content approximately equal to that before processing, and the obtained dried green coffee beans were roasted at 235° C. using Gene Cafe (manufactured by JENESIS) until the L value reached 20, thereby obtaining roasted coffee beans (Vietnamese Robusta sample 2-1).

[0132] [Samples 2-2 to 2-8]

[0133] 100 g of green coffee beans of the Robusta species (produced in Vietnam) and 10 g, 20 g, 30 g, 40 g, 50 g, 60 g or 100 g of water at room temperature were placed in a heat-resistant container, which was covered with aluminum foil to prevent the water from escaping. The heat-resistant container was placed in an autoclave (LSX500, TOMY SEIKO Co., Ltd.), the temperature was raised from room temperature to 90° C., and the temperature was maintained for 30 minutes to perform a heat treatment.

[0134] Roasted coffee beans (Vietnam-produced Robusta samples 2-2 to 2-8) were obtained in the same manner as in sample 2-1 except for the above.

[0135] [Sample 2-9]

[0136] 100 g of Robusta green coffee beans (produced in Vietnam) and 40 g of water at room temperature were placed in a heat-resistant container, and roasted coffee beans (Vietnam Robusta Sample 2-9) were obtained in the same manner as in Sample 2-1 except that the heat treatment was not performed.

[0137] (2) Coffee extract

[0138] For samples 2-1 to 2-9, the same operation as controls A and B was performed to prepare coffee extracts.

[0139] (3) Determination of indole and skatole content in coffee extract

[0140] The contents of indole and skatole were measured for samples 2-1 to 2-9 in the same manner as controls A and B. The number of data for each condition was set to 3, and the average value was calculated and used as the quantitative value.

[0141] (4) Measurement results

[0142] The quantitative values ​​and standard deviations of indole and skatole for each sample are summarized in Table 2. Figure 2 A comparison chart of the quantitative values ​​of indole (upper panel) and skatole (lower panel) of each sample is shown in FIG.

[0143] [Table 2]

[0144]

[0145] (5) Investigation

[0146] It was confirmed that the content of indole or skatole in the extract obtained from the green coffee beans of the Examples processed by adding 10% by mass or more of water, heating, and adding an organic acid was significantly lower than that of the extracts obtained from any of the Control Examples and Comparative Examples.

[0147] Experiment 3 Effect of the amount of organic acid added to green coffee beans

[0148] (1) Roasted coffee beans

[0149] [Samples 3-1 to 3-4]

[0150] 100 g of green coffee beans of the Robusta species (produced in Vietnam) and 40 g of water at room temperature were placed in a heat-resistant container, which was covered with aluminum foil to prevent the water from escaping. The heat-resistant container was placed in an autoclave (LSX500, TOMY SEIKO Co., Ltd.), the temperature was raised from room temperature to 90° C., and the temperature was maintained for 30 minutes to perform a heat treatment.

[0151] 0.7, 1, 3 or 5 g of lactic acid was added to the heat-treated green coffee beans based on 100 g of the green coffee beans before processing, and the mixture was left to be absorbed at room temperature for 3 hours.

[0152] Thereafter, the coffee beans were dried to a moisture content of about the amount before processing, and the dried processed green coffee beans obtained were roasted at 235° C. using Gene Cafe (manufactured by JENESIS) until the L value reached 20, thereby obtaining roasted coffee beans (Vietnamese Robusta samples 3-1 to 3-4).

[0153] (2) Coffee extract

[0154] For samples 3-1 to 3-4, the same operation as controls A and B was performed to prepare coffee extracts.

[0155] (3) Determination of indole and skatole content in coffee extract

[0156] The contents of indole and skatole were measured for samples 3-1 to 3-4 in the same manner as controls A and B. The number of data for each condition was set to 3, and the average value was calculated and used as the quantitative value.

[0157] (4) Evaluation results

[0158] The quantitative values ​​and standard deviations of indole and skatole for each sample are summarized in Table 3. Figure 3 A comparison chart of the quantitative values ​​of indole (upper panel) and skatole (lower panel) of each sample is shown in FIG.

[0159] [Table 3]

[0160]

[0161] (5) Investigation

[0162] It was confirmed that the content of indole or skatole in the extract obtained from the green coffee beans of the examples processed by adding water, heating, and adding 0.7 mass % or more of an organic acid was significantly lower than that in the extracts obtained from any of the control examples.

[0163] Experiment 4 Effect of adding sugar to green coffee beans

[0164] (1) Roasted coffee beans

[0165] [Samples 4-1 to 4-3]

[0166] 100 g of green coffee beans of the Robusta species (produced in Vietnam) and 40 g of water at room temperature were placed in a heat-resistant container, which was covered with aluminum foil to prevent the water from escaping. The heat-resistant container was placed in an autoclave (LSX500, TOMY SEIKO Co., Ltd.), the temperature was raised from room temperature to 90° C., and the temperature was maintained for 30 minutes to perform a heat treatment.

[0167] 3 g of sugar (fructose, maltose, or glucose) was added to the heat-treated green coffee beans based on 100 g of the green coffee beans before processing, and the mixture was left to be absorbed at room temperature for 3 hours.

[0168] Thereafter, the coffee beans were dried to a moisture content of about the amount before processing, and the dried processed green coffee beans obtained were roasted at 235° C. using Gene Cafe (manufactured by JENESIS) until the L value reached 20, thereby obtaining roasted coffee beans (Vietnamese Robusta samples 4-1 to 4-3).

[0169] (2) Coffee extract

[0170] For samples 4-1 to 4-3, the same operation as controls A and B was performed to prepare coffee extracts.

[0171] (3) Determination of indole and skatole content in coffee extract

[0172] The contents of indole and skatole were measured for samples 4-1 to 4-3 in the same manner as controls A and B. The number of data for each condition was set to 3, and the average value was calculated and used as the quantitative value.

[0173] (4) Evaluation results

[0174] The quantitative values ​​and standard deviations of indole and skatole for each sample are summarized in Table 4. Figure 4 A comparison chart of the quantitative values ​​of indole (upper panel) and skatole (lower panel) of each sample is shown in FIG.

[0175] [Table 4]

[0176]

[0177] (5) Investigation

[0178] It was confirmed that the content of indole or skatole in the extract obtained from the green coffee beans of the examples processed by adding water, heating and sugar was significantly lower than that of the extract obtained from any of the control examples. It was confirmed that the content of indole or skatole was further reduced when fructose or glucose was used as sugar.

[0179] Experiment 5 Effect of the amount of water added to green coffee beans

[0180] (1) Roasted coffee beans

[0181] [Sample 5-1]

[0182] 100 g of Robusta green coffee beans (produced in Vietnam) were placed in a heat-resistant container and covered with aluminum foil to prevent moisture from escaping. The heat-resistant container was placed in an autoclave (LSX500, TOMY SEIKO Co., Ltd.), and the temperature was raised from room temperature to 90° C. and maintained at this temperature for 30 minutes to perform a heat treatment.

[0183] 3 g of glucose was added to the heat-treated green coffee beans based on 100 g of the green coffee beans before processing, and the mixture was left to be absorbed at room temperature for 3 hours.

[0184] Thereafter, the coffee beans were dried to a moisture content approximately equal to that before processing, and the obtained dried green coffee beans were roasted at 235° C. using Gene Cafe (manufactured by JENESIS) until the L value reached 20, thereby obtaining roasted coffee beans (Vietnamese Robusta sample 5-1).

[0185] [Samples 5-2 to 5-8]

[0186] 100 g of green coffee beans of the Robusta species (produced in Vietnam) and 10 g, 20 g, 30 g, 40 g, 50 g, 60 g or 100 g of water at room temperature were placed in a heat-resistant container, which was covered with aluminum foil to prevent the water from escaping. The heat-resistant container was placed in an autoclave (LSX500, TOMY SEIKO Co., Ltd.), the temperature was raised from room temperature to 90° C., and the temperature was maintained for 30 minutes to perform a heat treatment.

[0187] Except for the above, the same operation as in Sample 5-1 was carried out to obtain roasted coffee beans (Vietnamese Robusta samples 5-2 to 5-8).

[0188] [Sample 5-9]

[0189] 100 g of green Robusta coffee beans (produced in Vietnam) and 40 g of water at room temperature were placed in a heat-resistant container and roasted coffee beans (Vietnam-produced Robusta Sample 5-9) were obtained in the same manner as in Sample 5-1 except that the heating treatment was not performed.

[0190] (2) Coffee extract

[0191] For samples 5-1 to 5-9, the same operation as controls A and B was performed to prepare coffee extracts.

[0192] (3) Determination of indole and skatole content in coffee extract

[0193] The contents of indole and skatole were measured for samples 5-1 to 5-9 in the same manner as controls A and B. The number of data for each condition was set to 3, and the average value was calculated and used as the quantitative value.

[0194] (4) Measurement results

[0195] The quantitative values ​​and standard deviations of indole and skatole for each sample are summarized in Table 5. Figure 5 A comparison chart of the quantitative values ​​of indole (upper panel) and skatole (lower panel) of each sample is shown in FIG.

[0196] [Table 5]

[0197]

[0198] (5) Investigation

[0199] It was confirmed that the content of indole or skatole in the extract obtained from the green coffee beans of the Examples processed by adding 10% by mass or more of water, heating, and adding sugars was significantly lower than that of the extracts obtained from any of the Control Examples and Comparative Examples.

[0200] Experiment 6 Effect of the amount of sugar added to green coffee beans

[0201] (1) Roasted coffee beans

[0202] [Samples 6-1 to 6-4]

[0203] 100 g of green coffee beans of the Robusta species (produced in Vietnam) and 40 g of water at room temperature were placed in a heat-resistant container, which was covered with aluminum foil to prevent the water from escaping. The heat-resistant container was placed in an autoclave (LSX500, TOMY SEIKO Co., Ltd.), the temperature was raised from room temperature to 90° C., and the temperature was maintained for 30 minutes to perform a heat treatment.

[0204] 0.7, 1, 3, or 5 g of glucose was added to the heat-treated green coffee beans based on 100 g of the green coffee beans before processing, and the mixture was left to absorb the glucose at room temperature for 3 hours.

[0205] Thereafter, the coffee beans were dried to a moisture content of about the amount before processing, and the dried processed green coffee beans obtained were roasted at 235° C. using Gene Cafe (manufactured by JENESIS) until the L value reached 20, thereby obtaining roasted coffee beans (Vietnamese Robusta samples 6-1 to 6-4).

[0206] (2) Coffee extract

[0207] For samples 6-1 to 6-4, the same operation as controls A and B was performed to prepare coffee extracts.

[0208] (3) Determination of indole and skatole content in coffee extract

[0209] The contents of indole and skatole were measured for samples 6-1 to 6-4 in the same manner as controls A and B. The number of data for each condition was set to 3, and the average value was calculated and used as the quantitative value.

[0210] (4) Evaluation results

[0211] The quantitative values ​​and standard deviations of indole and skatole for each sample are summarized in Table 6. Figure 6 A comparison chart of the quantitative values ​​of indole (upper panel) and skatole (lower panel) of each sample is shown in FIG.

[0212] [Table 6]

[0213]

[0214] (5) Investigation

[0215] It was confirmed that the content of indole or skatole in the extract obtained from the green coffee beans of the examples processed by adding water, heating, and adding 0.7 mass % or more of sugars was significantly lower than that of the extracts obtained from any of the control examples.

[0216] Experiment 7 Effects of adding organic acids and sugars to green coffee beans

[0217] (1) Roasted coffee beans

[0218] [Samples 7-1 to 7-4]

[0219] 100 g of green coffee beans of the Robusta species (produced in Vietnam) and 40 g of water at room temperature were placed in a heat-resistant container, which was covered with aluminum foil to prevent the water from escaping. The heat-resistant container was placed in an autoclave (LSX500, TOMY SEIKO Co., Ltd.), the temperature was raised from room temperature to 90° C., and the temperature was maintained for 30 minutes to perform a heat treatment.

[0220] To the heat-treated green coffee beans, 0.7 g of lactic acid and 0.7 g of glucose, 1 g of lactic acid and 1 g of glucose, 3 g of lactic acid and 3 g of glucose, or 5 g of lactic acid and 10 g of glucose were added based on 100 g of the green coffee beans before processing, and left to be absorbed at room temperature for 3 hours.

[0221] Thereafter, the coffee beans were dried to a moisture content of about the amount before processing, and the dried processed green coffee beans obtained were roasted at 235° C. using Gene Cafe (manufactured by JENESIS) until the L value reached 20, thereby obtaining roasted coffee beans (Vietnamese Robusta samples 7-1 to 7-4).

[0222] (2) Coffee extract

[0223] For samples 7-1 to 7-4, the same operation as controls A and B was performed to prepare coffee extracts.

[0224] (3) Determination of indole and skatole content in coffee extract

[0225] The contents of indole and skatole were measured for samples 7-1 to 7-4 in the same manner as controls A and B. The number of data for each condition was set to 3, and the average value was calculated and used as the quantitative value.

[0226] (4) Evaluation results

[0227] The quantitative values ​​and standard deviations of indole and skatole for each sample are summarized in Table 7. Figure 7 A comparison chart of the quantitative values ​​of indole (upper panel) and skatole (lower panel) of each sample is shown in FIG.

[0228] [Table 7]

[0229]

[0230] (5) Investigation

[0231] It was confirmed that the content of indole or skatole in the extract obtained from the green coffee beans of the examples processed by adding water, heating, and adding organic acids and sugars was significantly lower than that in the extracts obtained from any of the control examples.

[0232] Experiment 8 Effect of the amount of water added to green coffee beans

[0233] (1) Roasted coffee beans

[0234] [Sample 8-1]

[0235] 100 g of Robusta green coffee beans (produced in Vietnam) were placed in a heat-resistant container, which was covered with aluminum foil to prevent moisture from escaping. The heat-resistant container was placed in an autoclave (LSX500, TOMY SEIKO Co.), heated from room temperature to 90° C., and maintained at this temperature for 30 minutes to perform heating processing.

[0236] 3 g of an organic acid mixed solution (lactic acid:acetic acid:citric acid=4:1:1 mass ratio) and 3 g of glucose were added to 100 g of the green coffee beans before processing, and the mixture was left to absorb at room temperature for 3 hours.

[0237] Thereafter, the coffee beans were dried to a moisture content approximately equal to that before processing, and the obtained dried green coffee beans were roasted at 235° C. using Gene Cafe (manufactured by JENESIS) until the L value reached 20, thereby obtaining roasted coffee beans (Vietnamese Robusta sample 8-1).

[0238] [Samples 8-2 to 8-8]

[0239] 100 g of green coffee beans of the Robusta species (produced in Vietnam) and 10 g, 20 g, 30 g, 40 g, 50 g, 60 g or 100 g of water at room temperature were placed in a heat-resistant container, which was covered with aluminum foil to prevent the water from escaping. The heat-resistant container was placed in an autoclave (LSX500, TOMY SEIKO Co., Ltd.), the temperature was raised from room temperature to 90° C., and the temperature was maintained for 30 minutes to perform a heat treatment.

[0240] Except for the above, the same operation as sample 8-1 was carried out to obtain roasted coffee beans (Vietnamese Robusta samples 8-2 to 8-8).

[0241] [Sample 8-9]

[0242] 100 g of green Robusta coffee beans (produced in Vietnam) and 40 g of water at room temperature were placed in a heat-resistant container and roasted coffee beans (Vietnam-produced Robusta Sample 8-9) were obtained in the same manner as in Sample 8-1 except that the heating treatment was not performed.

[0243] (2) Coffee extract

[0244] For samples 8-1 to 8-9, the same operation as controls A and B was performed to prepare coffee extracts.

[0245] (3) Determination of indole and skatole content in coffee extract

[0246] For samples 8-1 to 8-9, the contents of indole and skatole were measured in the same manner as controls A and B. The number of data for each condition was set to 3, and the average value was calculated and used as the quantitative value.

[0247] (4) Measurement results

[0248] The quantitative values ​​and standard deviations of indole and skatole for each sample are summarized in Table 8. Figure 8 A comparison chart of the quantitative values ​​of indole (upper panel) and skatole (lower panel) of each sample is shown in FIG.

[0249] [Table 8]

[0250]

[0251] (5) Investigation

[0252] It was confirmed that the content of indole or skatole in the extract obtained from the green coffee beans of the Examples processed by adding 10% by mass or more of water, heating, and adding an organic acid and a sugar was significantly lower than that of the extracts obtained from any of the Control Examples and Comparative Examples.

[0253] Experiment 9 Effects of adding organic acids and sugars to green coffee beans

[0254] (1) Roasted coffee beans

[0255] [Comparison C]

[0256] 100 g of Robusta green coffee beans (produced in Uganda) were roasted at 235° C. using Gene Cafe (manufactured by JENESIS) until the L value reached 20, thereby obtaining roasted coffee beans (Uganda Robusta control C).

[0257] [Sample 9-1]

[0258] 100 g of green coffee beans of the Robusta species (produced in Uganda) and 40 g of water at room temperature were placed in a heat-resistant container, which was covered with aluminum foil to prevent the water from escaping. The heat-resistant container was placed in an autoclave (LSX500, TOMY SEIKO Co., Ltd.), the temperature was raised from room temperature to 90° C., and the temperature was maintained for 30 minutes to perform a heat treatment.

[0259] 3 g of an organic acid mixed solution (lactic acid:acetic acid:citric acid=4:1:1 mass ratio) and 3 g of glucose were added to 100 g of the green coffee beans before processing, and the mixture was left at room temperature for 3 hours for absorption.

[0260] Thereafter, the coffee beans were dried to a moisture content approximately equal to that before processing, and the obtained dried processed green coffee beans were roasted at 235° C. using Gene Cafe (manufactured by JENESIS) until the L value reached 20, thereby obtaining roasted coffee beans (Uganda Robusta sample 9-1).

[0261] [Comparison D]

[0262] 100 g of Robusta green coffee beans (produced in Indonesia) were roasted at 235° C. using Gene Cafe (manufactured by JENESIS) until the L value reached 20, thereby obtaining roasted coffee beans (Indonesia-produced Robusta control D).

[0263] [Sample 9-2]

[0264] 100 g of green coffee beans of the Robusta species (produced in Indonesia) and 40 g of water at room temperature were placed in a heat-resistant container, which was covered with aluminum foil to prevent the water from escaping. The heat-resistant container was placed in an autoclave (LSX500, TOMY SEIKO Co., Ltd.), the temperature was raised from room temperature to 90° C., and the temperature was maintained for 30 minutes to perform a heat treatment.

[0265] 3 g of an organic acid mixed solution (lactic acid:acetic acid:citric acid=4:1:1 mass ratio) and 3 g of glucose were added to 100 g of the green coffee beans before processing, and the mixture was left to absorb at room temperature for 3 hours.

[0266] Thereafter, the coffee beans were dried to a moisture content of about the amount before processing, and the obtained dried processed green coffee beans were roasted at 235° C. using Gene Cafe (manufactured by JENESIS) until the L value reached 20, thereby obtaining roasted coffee beans (Indonesian Robusta sample 9-2).

[0267] (2) Coffee extract

[0268] For Control C, Sample 9-1, Control D, and Sample 9-2, roasted coffee beans were crushed to the minimum particle size of a cone mill (DeLonghi SpA) to obtain roasted bean powder. After 180 mL of hot water was poured into 10 g of the roasted bean powder and kept for 4 minutes, the whole was stirred and mixed, and the bubbles remaining on the surface were removed. Thereafter, the mixture was kept for 12 minutes from the time of the hot water injection (ie, the extraction time was set to 12 minutes), and the supernatant after the roasted bean powder was naturally settled was recovered as a coffee extract.

[0269] (3) Determination of indole and skatole content in coffee extract

[0270] 3-methyl-1H-indole-d8 (obtained from Toronto Research Chemicals Inc.) was dissolved in 50% methanol aqueous solution by volume at a concentration of 100 ng / mL as an internal standard solution. After mixing 25 μL of the internal standard solution, 400 μL of 50% methanol aqueous solution by volume and 100 μL of each coffee extract, the mixture was filtered using a PTFE filter with a pore size of 0.2 μm, and the filtrate was used as an analytical sample. For the analytical sample, the content of indole and skatole was determined according to the following LC-MS / MS conditions. The number of data for each condition was set to 3, and the average value was calculated and used as the quantitative value.

[0271] (4) Measurement results

[0272] The quantitative values ​​and standard deviations of indole and skatole for each sample are summarized in Table 9. Fig. 9 A comparison chart of the quantitative values ​​of indole (upper panel) and skatole (lower panel) of each sample is shown in FIG.

[0273] [Table 9]

[0274]

[0275] (5) Investigation

[0276] It was confirmed that the content of indole or skatole in the extract obtained from the green coffee beans of the Examples processed by adding water, heating, and adding organic acids and sugars was significantly lower than that of the extract obtained from any of the control examples, regardless of the origin of the coffee beans.

[0277] Experiment 10 Effects of adding organic acids and sugars to green coffee beans

[0278] (1) Roasted coffee beans

[0279] [Comparison E]

[0280] 100 g of Arabica green coffee beans (produced in Brazil) were roasted at 235° C. using Gene Cafe (manufactured by JENESIS) until the L value reached 20, thereby obtaining roasted coffee beans (Brazilian Arabica control E).

[0281] [Sample 10-1]

[0282] 100 g of Arabica green coffee beans (produced in Brazil) and 40 g of water at room temperature were placed in a heat-resistant container, which was covered with aluminum foil to prevent the water from escaping. The heat-resistant container was placed in an autoclave (LSX500, TOMY SEIKO Co., Ltd.), the temperature was raised from room temperature to 90° C., and the temperature was maintained for 30 minutes to perform a heat treatment.

[0283] 3 g of an organic acid mixed solution (lactic acid:acetic acid:citric acid=4:1:1 mass ratio) and 3 g of glucose were added to 100 g of the green coffee beans before processing, and the mixture was left at room temperature for 3 hours for absorption.

[0284] Thereafter, the coffee beans were dried to a moisture content approximately equal to that before processing, and the dried processed green coffee beans obtained were roasted at 235° C. using Gene Cafe (manufactured by JENESIS) until the L value reached 20, thereby obtaining roasted coffee beans (Brazilian Arabica sample 10-1).

[0285] [Sample 10-2]

[0286] 100 g of Arabica green coffee beans (produced in Brazil) were placed in a heat-resistant container, and roasted coffee beans (Brazilian Arabica sample 10-2) were obtained in the same manner as in Sample 10-1 except that no water was added.

[0287] [Sample 10-3]

[0288] 100 g of Arabica green coffee beans (produced in Brazil) and 40 g of water at room temperature were placed in a heat-resistant container and roasted coffee beans (Brazilian Arabica sample 10-3) were obtained in the same manner as in Sample 10-1 except that the heating treatment was not performed.

[0289] [Sample 10-4]

[0290] Roasted coffee beans (Brazilian Arabica sample 10-4) were obtained in the same manner as in Sample 10-1 except that organic acids and sugars were not added to the heat-treated green coffee beans.

[0291] (2) Coffee extract

[0292] For control E and samples 10-1 to 10-4, roasted coffee beans were crushed to the minimum particle size of a cone mill (DeLonghi S.pA) to obtain roasted bean powder. After 180 mL of hot water was poured into 10 g of the roasted bean powder and kept for 4 minutes, the whole was stirred and mixed to remove the bubbles remaining on the surface. Thereafter, the mixture was kept for 12 minutes from the time of the hot water injection (ie, the extraction time was set to 12 minutes), and the supernatant after the roasted bean powder was naturally precipitated was recovered as a coffee extract.

[0293] (3) Determination of indole and skatole content in coffee extract

[0294] 3-methyl-1H-indole-d8 (obtained from Toronto Research Chemicals Inc.) was dissolved in 50% methanol aqueous solution by volume at a concentration of 100 ng / mL as an internal standard solution. After mixing 25 μL of the internal standard solution, 400 μL of 50% methanol aqueous solution by volume and 100 μL of each coffee extract, the mixture was filtered using a PTFE filter with a pore size of 0.2 μm, and the filtrate was used as an analytical sample. For the analytical sample, the content of indole and skatole was determined according to the following LC-MS / MS conditions. The number of data for each condition was set to 3, and the average value was calculated and used as the quantitative value.

[0295] (4) Measurement results

[0296] The quantitative values ​​and standard deviations of indole and skatole for each sample are summarized in Table 10. Fig.10 A comparison chart of the quantitative values ​​of indole (upper panel) and skatole (lower panel) of each sample is shown in FIG.

[0297] [Table 10]

[0298]

[0299] (5) Investigation

[0300] It was confirmed that the content of indole or skatole in the extract obtained from the green coffee beans of the Examples processed by adding water, heating, and adding organic acids and sugars was significantly lower than that of the extracts obtained from any of the Control Examples and Comparative Examples, regardless of the variety of the coffee beans.

[0301] Experiment 11: Is there any drying effect after green coffee beans absorb organic acids and sugars?

[0302] (1) Roasted coffee beans

[0303] [Sample 11]

[0304] (1) Roasted coffee beans

[0305] An organic acid mixed solution (lactic acid:acetic acid:citric acid=4:1:1 mass ratio) and glucose were added to the heat-treated green coffee beans, and the mixture was left to absorb at room temperature for 3 hours. Roasted coffee beans (Vietnamese Robusta Sample 11) were obtained in the same manner as Sample 8-5 except that the mixture was not dried.

[0306] (2) Coffee extract

[0307] For sample 11, the same operation as controls A and B was performed to prepare a coffee extract.

[0308] (3) Determination of indole and skatole content in coffee extract

[0309] For Sample 11, the same operations as for Controls A and B were performed to determine the contents of indole and skatole. The number of data for each condition was set to 3, and the average value was calculated and used as the quantitative value.

[0310] (4) Measurement results

[0311] The quantitative values and standard deviations of indole and skatole for each sample were summarized in Table 11, Fig.11 and a comparison chart of the quantitative values of indole (upper part) and skatole (lower part) for each sample is shown.

[0312] [Table 11]

[0313]

[0314] (5) Discussion

[0315] It was confirmed that the content of indole or skatole in the extract obtained from the green coffee beans of the examples processed by adding water, heating, and adding organic acids and sugars was significantly reduced compared to the extract obtained from any control example, regardless of whether it was dried after absorbing organic acids and sugars.

[0316] [Measurement method]

[0317] [LC-MS / MS conditions]

[0318] Using 3-methyl-1H-indole-d8 as the internal standard, the quantitative method was determined using the multiple reaction monitoring mode. Indole (obtained from Nacalai Tesque) and skatole (obtained from Tokyo Chemical Industry Co., Ltd.) were each diluted with a 50% by volume methanol aqueous solution to prepare a standard curve for each compound. Thereafter, the concentration of the compound contained in the coffee extract sample pretreated by the aforementioned method was quantified.

[0319] Specifically, the column used was Shim-pack Scepter C18-120 (1.9 μm, 2.1 mm×50 mm) manufactured by Shimadzu Corporation. As the LC-MS / MS equipment, the high performance liquid chromatography (HPLC) system used was Nextera HPLC system manufactured by Shimadzu Corporation (communication information transfer channel module: CBM-20A; pump: LC-30AD; autosampler: SIL-30AC; degasser: DGU-20A5R; column oven: CTO-20AC), and the tandem mass spectrometry (MS / MS) system used was SciexTriple quad 6500+ manufactured by AB SCIEX Corporation. Mobile phase A used 0.05 vol% formic acid aqueous solution, mobile phase B used 100 vol% methanol, the flow rate was set to 0.2 mL / min, and the column temperature was set to 40°C. The following conditions were used: as the initial concentration, the mobile phase A:B volume ratio was 45:55, and the concentration was maintained under the same conditions for 5 minutes. After 0.1 minutes, the concentration was set to 0:100, and the concentration was maintained under the same conditions for 2 minutes. The injection volume into the HPLC was 2 μL.

[0320] Regarding MS conditions, the ionization mode was APCI positive ion mode. Among the MS conditions, the following 6 types: Curtain gas, Collision activated dissociation gas, Ion spray voltage floating, Temperature, Ion source gas 1, and Entrance potential are common parameters for compounds, which are summarized in Table 12. Among the MS conditions, the following 6 types: Declustering potential, Collision energy, Collision cell exit potential, Elution time, Precursor ion, and Product ion are parameters set for each compound, which are summarized in Table 13.

[0321] [Table 12]

[0322]

[0323] [Table 13]

[0324]

[0325] <Method for measuring L value>

[0326] The L value was measured using a color difference meter Color meter ZE6000 manufactured by Nippon Denshoku Industries Co., Ltd. Specifically, 10 g of roasted coffee beans were pulverized to the minimum particle size using a conical mill (DeLonghi S.p.A), the obtained powder was put into the attached round dish and compacted, and the L value in the reflection mode of the color difference meter was measured.

[0327] Industrial applicability

[0328] In the prior art, it is necessary to heat green coffee beans at a high temperature of 100 °C or higher, so high-pressure heating equipment is required. However, according to the method for reducing indole and skatole in roasted coffee beans of the present invention, it is possible to suppress the formation of specific unpleasant odor components (indole and skatole) generated in roasted coffee beans in a short time under heating conditions below 100 °C. Thus, the method for manufacturing roasted coffee beans of the present invention adopts the above reduction method, and it is possible to manufacture roasted coffee beans with a significantly reduced content of indole and skatole as unpleasant odor components using simple equipment.

Claims

1. A method for producing roasted coffee beans, comprising the following steps: (1) A step of adding 10% by mass or more of water to green coffee beans; (2) after the step of adding water, heating the green coffee beans and the water to a temperature lower than 100° C. under atmospheric pressure to allow the water to penetrate into the green coffee beans; (3) after the step of impregnating with water, a step of allowing the green coffee beans impregnated with water to absorb organic acids and / or sugars; and (4) After the step of absorbing the organic acid and / or sugar, a step of roasting the green coffee beans that have absorbed the organic acid and / or sugar.

2. The manufacturing method according to claim 1, wherein: In the step of absorbing the organic acid and / or sugar, the aqueous solution containing the organic acid and / or sugar is impregnated into the green coffee beans impregnated with water.

3. The manufacturing method according to claim 1 or 2, wherein: The organic acid is at least one selected from the group consisting of lactic acid, citric acid and acetic acid, and the sugar is at least one selected from the group consisting of glucose, fructose and maltose.

4. The production method according to any one of claims 1 to 3, wherein The organic acid or sugar is absorbed in an amount of 0.5 mass % or more based on the green coffee beans.

5. The production method according to any one of claims 1 to 4, wherein The green coffee beans are of the Robusta variety. 6 . Roasted coffee beans produced by the production method according to claim 1 .

7. A food or beverage comprising the roasted coffee beans or an extract thereof according to claim 6.

8. A method for reducing indole and skatole in roasted coffee beans, comprising the following steps: (1) A step of adding 10% by mass or more of water to green coffee beans; (2) after the step of adding water, heating the green coffee beans and the water to a temperature lower than 100° C. under atmospheric pressure to allow the water to penetrate into the green coffee beans; (3) after the step of impregnating with water, a step of allowing the green coffee beans impregnated with water to absorb organic acids and / or sugars; and (4) After the step of absorbing the organic acid and / or sugar, a step of roasting the green coffee beans that have absorbed the organic acid and / or sugar.

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